Let's go through each question and explain the solutions step by step.
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Q.3: Label the diagram below which shows the carbon cycle.
The diagram already has most labels, but let’s clarify what each part represents in the
carbon cycle:
1.
Sun → Photosynthesis:
- The sun provides energy for
photosynthesis, where plants absorb
CO₂ from the atmosphere to produce glucose and oxygen.
2.
Photosynthesis → Plant Respiration:
- Plants use
respiration (like animals) to release energy from glucose, producing
CO₂ as a waste product.
3.
Plant Respiration → Atmosphere (CO₂):
- CO₂ is released back into the air.
4.
Animals (cow and sheep) → Animal Respiration:
- Animals consume plants and respire, releasing
CO₂ into the atmosphere.
5.
Dead organisms and waste products → Decay organisms:
- When organisms die,
decomposers (like bacteria and fungi) break down their remains, releasing
CO₂ via
decomposition.
6.
Fossil fuels → Auto and factory emissions:
- Over millions of years, dead organisms form
fossil fuels (coal, oil, gas). When burned (combustion), they release
CO₂ into the atmosphere.
7.
Auto and factory emissions → CO₂ in atmosphere:
- Human activities like burning fossil fuels in cars and factories add large amounts of CO₂.
8.
Decay organisms → Fossil fuels:
- Some dead organic matter gets buried and over time turns into fossil fuels.
9.
Fossil fuels → CO₂ (via combustion):
- When fossil fuels are burned, they release stored carbon as CO₂.
✔ So, the diagram correctly shows:
-
Photosynthesis (absorbs CO₂)
-
Respiration (releases CO₂)
-
Decomposition (releases CO₂)
-
Combustion (from fossil fuels and vehicles)
-
Carbon storage in soil and fossil fuels
> ✔️ The diagram is already labeled correctly with key processes.
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Q.4: Carbon dioxide is produced by the human body through _____________.
Answer: b) respiration
####
✔ Explanation:
- Humans perform
cellular respiration to produce energy.
- In this process, glucose + oxygen → carbon dioxide + water + energy.
-
CO₂ is a waste product exhaled from the lungs.
- This is
not combustion (which involves burning fuel), photosynthesis (only in plants), or decomposition (which happens after death).
> 🔍 So,
respiration is the correct answer.
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Q.5: Carbon dioxide from living things is also returned to the atmosphere through processes of _________ of dead tissue.
Answer: d) decomposition
####
✔ Explanation:
- After organisms die, their bodies are broken down by
decomposers (bacteria, fungi).
- During
decomposition, organic matter is oxidized, releasing
CO₂ into the atmosphere.
- This is different from:
-
Combustion – burning of materials (e.g., fossil fuels).
-
Respiration – occurs in living organisms.
-
Photosynthesis – absorbs CO₂, doesn’t release it.
> 🔍 Therefore,
decomposition is the correct process for returning carbon from dead tissue to the atmosphere.
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✔ Final Answers:
-
Q.3: Diagram is correctly labeled (no changes needed).
-
Q.4: b) respiration
-
Q.5: d) decomposition
Let me know if you'd like a simplified version or a diagram explanation!
Parent Tip: Review the logic above to help your child master the concept of carbon cycle worksheet high school.
